A5053437621- Hydrology and Watershed Management Studies
- Plant Water Relations and Carbon Dynamics
- Soil and Unsaturated Flow
- Groundwater flow and contamination studies
- Groundwater and Isotope Geochemistry
- Cryospheric studies and observations
- Geology and Paleoclimatology Research
- Atmospheric and Environmental Gas Dynamics
- Landslides and related hazards
- Microbial Community Ecology and Physiology
- Flood Risk Assessment and Management
- Tree-ring climate responses
- Isotope Analysis in Ecology
- Soil and Water Nutrient Dynamics
- Precipitation Measurement and Analysis
- Plant responses to water stress
- Soil Carbon and Nitrogen Dynamics
- Species Distribution and Climate Change
- Advanced Chemical Sensor Technologies
- Hydrocarbon exploration and reservoir analysis
- Peatlands and Wetlands Ecology
- Fecal contamination and water quality
- Climate variability and models
- Analytical Chemistry and Sensors
- Plant Ecology and Soil Science
University of Arizona
2008-2022
Accenture (Germany)
2020-2022
Oracle (United States)
2020-2022
Accenture (Switzerland)
2020
Sphere Medical (United Kingdom)
2018
University of Freiburg
2010-2016
Summary Plants rely primarily on rainfall infiltrating their root zones – a supply that is inherently variable, and fluctuations are predicted to increase most of the Earth's surface. Yet, interrelationships between water availability plant use short timescales difficult quantify remain poorly understood. To overcome previous methodological limitations, we coupled high‐resolution in situ observations stable isotopes soil transpiration water. We applied approach along with Bayesian mixing...
Abstract. In this commentary, we summarize and build upon discussions that emerged during the workshop “Isotope-based studies of water partitioning plant–soil interactions in forested agricultural environments” held San Casciano Val di Pesa, Italy, September 2017. Quantifying understanding how cycles through Earth's critical zone is important to provide society policymakers with scientific background manage resources sustainably, especially considering ever-increasing worldwide concern about...
Abstract. Stable water isotopes are widely used in ecohydrology to trace the transport, storage, and mixing of on its journey through landscapes ecosystems. Evaporation leaves a characteristic signature isotopic composition that is left behind, such dual-isotope space, evaporated waters plot below local meteoric line (LMWL) characterizes precipitation. Soil xylem samples can often LMWL as well, suggesting they have also been influenced by evaporation. These soil frequently along linear...
Abstract. Stable isotope signatures provide an integral fingerprint of origin, flow paths, transport processes, and residence times water in the environment. However, full potential stable isotopes to quantitatively characterize subsurface dynamics is yet unfolded due difficulty obtaining extensive, detailed, repeated measurements pore unsaturated saturated zone. This paper presents a functional cost-efficient system for non-destructive continual situ monitoring with high resolution....
Abstract Field studies analyzing the stable isotope composition of xylem water are providing important information on ecosystem relations. However, capacity isotopes to characterize functioning plants in their environment has not been fully explored because methodological constraints extent and resolution at which samples could be collected analysed. Here, we introduce an situ method offering potential continuously monitor tree via its vapour phase using a commercial laser‐based analyser...
Abstract. Determining the soil hydraulic properties is a prerequisite to physically model transient water flow and solute transport in vadose zone. Estimating these by inverse modelling techniques has become more common within last 2 decades. While approaches usually fit simulations hydrometric data, we expanded methodology using independent information about stable isotope composition of pore depth profile as single or additional optimization target. To demonstrate potential limits this...
Abstract Transit times through hydrologic systems vary in time, but the nature of that variability is not well understood. was investigated a 1 m 3 sloping lysimeter, representing simplified model hillslope receiving periodic rainfall events for 28 days. Tracer tests were conducted using an experimental protocol allows time‐variable transit time distributions (TTDs) to be calculated from data. Observed TTDs varied with storage state system, and history inflows outflows. We propose observed...
Despite the availability of weather radar data at high spatial (1 km 2 ) and temporal (5–15 min) resolution, ground‐based rain gauges continue to be necessary for accurate estimation storm rainfall input catchments during flash flood events, especially in mountainous catchments. Given economical considerations, a long‐standing problem catchment hydrology is establish optimal placement small number acquire on both depth spatiotemporal variability intensity extreme events. Using observations...
Abstract Distributions of water transit times (TTDs), and related storage‐selection (SAS) distributions, are spatially integrated metrics hydrological transport within landscapes. Recent works confirm that the form TTDs SAS distributions should be considered time variant—possibly depending, in predictable ways, on dynamic storage landscape. We report a 28 day periodic‐steady‐state‐tracer experiment performed model hillslope contained 1 m 3 sloping lysimeter. Using experimental data, we...
Abstract The hypothesis of ecohydrological separation (ES) proposes that the water contained in surface soils is not uniformly extracted by root uptake nor displaced infiltration. Rather vegetation selectively removes held under tension, and infiltrating wet soil will bypass much water‐filled pore space. Methodological differences across previous studies have contributed to disagreement concerning prevalence ES. We measured stable isotopes O H precipitation, snowpack, canopy throughfall,...
Abstract. Stable water isotopes are widely used in ecohydrology as tracers of the transport, storage, and mixing on its journey through landscapes ecosystems. Evaporation leaves a characteristic signature isotopic composition that is left behind, such dual-isotope space, evaporated waters plot below Local Meteoric Water Line (LMWL) characterizes precipitation. Soil xylem samples can often LMWL well, suggesting they have also been influenced by evaporation. These soil frequently along linear...
Soil fluxes of CO2 (Fs) have long been considered unidirectional, reflecting the predominant roles metabolic activity by microbes and roots in ecosystem carbon cycling. Nonetheless, there is a growing body evidence that non-biological processes soils can outcompete biological ones, pivoting from net source to sink CO2, as evident mainly hot cold deserts with alkaline soils. Widespread reporting unidirectional may lead misrepresentation Fs process-based models errors estimates local global...
Abstract Spatially integrated water transport dynamics at the hillslope scale have rarely been observed directly, and underlying physical mechanisms of those are poorly understood. We present time‐variable transit time distributions StorAge Selection (SAS) functions for a 28 days tracer experiment conducted Landscape Evolution Observatory, Biosphere 2, University Arizona, AZ, USA. The form SAS is concave, meaning that older in was preferentially discharged than younger water. concavity is,...
Abstract. This paper explores the challenges of model parameterization and process representation when simulating multiple hydrologic responses from a highly controlled unsaturated flow transport experiment with physically based model. The experiment, conducted at Landscape Evolution Observatory (LEO), involved alternate injections water deuterium-enriched into an initially very dry hillslope. multivariate observations included point measures content tracer concentration in soil, total...
Abstract Hillslopes turn precipitation into runoff and thus exert important controls on various Earth system processes. It remains difficult to collect reliable data necessary for understanding modeling these processes in real catchments. To overcome this problem, controlled experiments are being conducted at the Landscape Evolution Observatory Biosphere 2, The University of Arizona. Previous have revealed differences hydrological response between 2 landscapes within Observatory, even though...
Abstract. Gas concentrations and isotopic signatures can unveil microbial metabolisms their responses to environmental changes in soil. Currently, few methods measure situ soil trace gases such as the products of nitrogen carbon cycling or volatile organic compounds (VOCs) that constrain biochemical processes like nitrification, methanogenesis, respiration, communication. Versatile gas sampling systems integrate probes with sensitive analyzers could fill this gap measurements resolve spatial...
Abstract. In this commentary, we build on discussions that emerged during the workshop "Isotope-based studies of water partitioning and plant-soil interactions in forested agricultural environments" held San Casciano Val di Pesa, Italy, September 2017. Quantifying understanding how cycles through Earth's critical zone is important to provide society policy makers with scientific background manage resources sustainably, especially considering ever-increasing worldwide concern about scarcity....
Abstract Soil microbes vigorously produce and consume gases that reflect active soil biogeochemical processes. gas measurements are therefore a powerful tool to monitor microbial activity. Yet, the majority of lack non-disruptive subsurface measurement methods at spatiotemporal scales relevant processes structure. To address this need, we developed sampling system uses novel diffusive probes sample transfer approaches for high-resolution from discrete regions. Probe requires transferring...
Abstract. The stable isotope signature of pore water provides an integral fingerprint origin, flow path, transport processes, and residence times can thus serve as a powerful tracer hydrological processes in the unsaturated saturated zone. However, full potential isotopes to quantitatively characterize subsurface dynamics is yet unfolded due difficulty obtaining extensive detailed continual measurements spatiotemporally variable signatures. With development field-deployable laser-based...
Microbial communities in incipient soil systems serve as the only biotic force shaping landscape evolution. However, underlying ecological forces microbial community structure and function are inadequately understood. We used amplicon sequencing to determine taxonomic assembly metagenome evaluate functional basaltic subjected precipitation. Community composition was stratified with depth pre-precipitation samples, surficial maintaining their distinct diversity after precipitation, while...
Abstract. Determining the soil hydraulic properties is a prerequisite to physically model transient water flow and solute transport in vadose zone. Estimating these by inverse modelling techniques has become more common within last two decades. While approaches usually fit simulations hydrometric data, we expanded methodology using independent information about stable isotope composition of pore depth profile as single or additional optimization target. To demonstrate potential limits this...
Abstract. This paper explores the challenges of model parameterization and process representation when simulating multiple hydrologic responses from a highly controlled unsaturated flow transport experiment with physically-based model. The experiment, conducted at Landscape Evolution Observatory (LEO), involved alternate injections water deuterium enriched into an initially very dry hillslope. multivariate observations included point measures content tracer concentration in soil, total...